Antioxidant or age retarder



Patented 'June 10, 1930 a; PATENT OFFICE"? ALBERT M.

\i e i IoDrawing.

invention relates to methods of treating rubber and the product formed thereby and it has particular relation to a method of treatment whereby the durability of rubber may be greatly enhanced.

More specifically, the invention has for one of its objects the provision of a material which, when it is incorporated into rubber compounds inhibits the absorption of oxyto gen and thus prevents premature loss of, elasticity and tensile strength of the rubber.

Another object of the invention is to provide a non-odorous and non-poisonous antioxidant or age-retarder which may readily be incorporated into rubber.

Another object of the invention is to provide an anti-oxidant or age-retarder which is highly eflicent in action and' which is relat1vely inexpensive to manufacture.

One difficulty heretofore ex erienced with rubber compounds has been ue to the absorption of oxygen which results in premature loss of elasticity and tensile strength of the compound. It has been proposed to overcome this diificulty by incorporating into the rubber prior to vulcanization a compound which inhibits the absorption of the oxygen. A relatively large number of compounds have been proposed for this purpose, but most at of them are more or less unsatisfactory for various reasons. Some of them exist normally only in a liquid state, and for that reason can be incorporated into the rubber only with considerable difliculty. Some of these materials also possess strong and unpleasant odors which render the handling thereof an unpleasant task. Still others are more or less poisonous in their nature and their use in rubber com ounds is likely to produce toxic effects upon the workmen employed in handling them. V

This invention consists in'the discovery that certain amino benzyl alcohols may be readily manufactured and incorporated into rubber compounds as antioxidants or age-retarders with highly gratifying results.

One material of this class is p- (a-naphthyl amido) benzyl alcohol which may be prepared by the following method.

Dissolve phenyl a-naphthylamine in alco- .L nnrroxrnan'r on AGE RETARDED Application filed March 1, 1928. Serial No. 258,442.

hol in the proportions of 16 grams of the amine to 27 5 cc. of alcohol. Treat this solution with 8.8 grams of h drochloric acid having a specific gravity 0 1.17 The resulting solution should then be treated with 5.45 grams of a forty percent solution of formaldehyde. It may be necessary to warm this solution slightly before reaction takes place. The reaction results in a curdy precipitate Which is allowed to stand until precipitation is com lete. The precipitate should then be filtere washed and suspended in alcohol. The alcoholic solution is next treated by makin it alkaline with ammonium hydroxide. s a'result of the latter treatment, a powder almost White in color and insoluble in alcohol is precipitated.

The same method may be employed in the manufacture of p-B-naphthyl amido benzyl alcohol by substituting phenyl ,B-naphthyL amine for phenyl a-naphthylamine.

The invention is not limited to the naphthylamido benzyl alcohols as antioxidants but includes also the phenyl amido benzyl alcohols and other alcohols of the class having the formula in which R represents a hydrocarbon group.

The substances just discussed may be employed in most of the standard rubber compounds with satisfactory results. The following is an example of a formula which insures a compound having excellent physlcal Samples of material prepared in accordance with the preceding formula in which the various materials disclosed were em-. ployed as antioxidants were subjected to vul canization. Certain of the vulcanized samples were then subjected to physical tests cmrronn, or nxnon, .onro, nssrenon 'ro -zrrm eoomznan'rmn a non IBEB COMPANY, or AKRON, OHIO, A oonroaArIoN or 01110 oxygen bomb containing oxygen under a pressure of 150 pounds per square inch and at a temperature of 50 C. The results of thfilse tests are indicated in the following ta es:

P-(phenylamido) benzyl alcohol ORIGINAL 4 i Stress in kgs/cm'at Steam Per cent Oureln %Elon DM- weight sure 500% 700% At at increase along. along. break AGE TEST so 4o 22 v 70' 105 775 .05 50 40 29 100 130 760 70 38 120 685 52 P- (a-naphthylamldo) benzyl alcohol ORIGINAL Stress in kgs/cm at Steam Per cent as. w a sure 500% 700% At crease elong. elong. break a AGE TEST a0 40 11 o1 iao s40 .12 50 40 25 90 160 805 11 70 40 34 124 165 750 14 P-(p-naphthylamido) benzyl alcohol ORIGINAL 7 Stress in kgs/cm at I Steam Per cent 91% 2 1.22% Weight sure 500% 700% At increase 411mg. elong. break AGE TEST It will be evident from the preceding description that the invention constitutes a novel and highly satisfactpr creasing the durability of ru ber compounds. The method does not involve the employment of any poisonous or malodorous materials. The compounds employed are also owderlike substances which may be: rea ily and method for ininvention or from the scope of the appended claims.

What I claim is: v

1. A method of treating rubber .which comprises incorporating therein an a-naphthylamido benzyl alcohol.

2.- A method of treating rubber which comprises incorporating therein a material having the following structural formula:

H R CGHCHZOHQ in which R is a radical selected from a group comprising a and ,B-naphthylene.

3. A method of treating rubber which com rises incorporating therein the reaction pro uct of a phenyl naphthylamine and an aldehyde, and sub ecting the resulting compound to vulcanization.

4. A method-of treating rubber which comprises incorporating therein a reaction product of henyl naphthylamine and an aldehyde and subjecting the resulting compound to vulcanization.

5. A method of treating rubber which com rises incor orating therein a reaction pro uct of a lienyl a-naphthylamine, and an aldehyde and sub ecting the resulting compound to vulcanization.

6. A rubber product that has been vulcanized in the presence of the reaction product of a phenyl naphthylamine and formaldehyde.

7. A rubber product that has bee vulcanized in the resence of the reactio prod-,. gotd of a phenyfnaphthylamine and an alde- 8. A rubber product that has been vulcanized in the presence of the reaction product'of a phenyl Jr-naphthylamine and formaldehyde.

v9. A rubber product that has been vulcanized in the presence of the reaction product of a material selected from a group comprising henyl a-naphthylamine and phenyl ,B-napht ylamine and formaldehyde.

In witness whereof, I have hereunto signed myoname.

Signed at Akron, in the county'of Summit and State of Ohio, U. S. A., this 29th day of February, 1928.

ALBERT M. CLIFFORD. 

